Career
In 2009, he started pro career with VEF Rīgeorgia After that season he went to Latvijas Universitāte, where he played next three seasons. Peiners helped his semi-pro team, which consisted of student athletes, to reach LBL playoffs twice.
In 2013, Žanis graduated from LU and attracted multiple clubs from abroad.
He had strong interest from Union Olimpija, but ultimately decided to sign with MBC Mykolaiv. He finished season in Ukrainian SuperLeague as the second best scorer (161ppg).
On September 17, 2014, he joined Latvian champs Ventspils.